Microwave-assisted ring-opening polymerization of poly (glycolic acid-co-lactic acid) copolymers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Guang Li ◽  
Na Zhao ◽  
Wei Bai ◽  
Dong Liang Chen ◽  
Cheng Dong Xiong
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Glycolic Acid ◽  
Raw Materials ◽  
Irradiation Time ◽  
Ring Opening Polymerization ◽  
Feed Ratio ◽  
Microwave Assisted Synthesis ◽  
Component Ratio ◽  
Microwave Assisted

AbstractThe microwave-assisted synthesis of poly(glycolic acid-co-lactic acid) (PGLA) copolymers by ring-opening polymerization of glycolide (GA) and L-lactide (L-LA) was studied. The microwave irradiation time and feed ratios on the molecular weights, as well as the thermal properties of the copolymers were discussed. These copolymers were characterized by 1H-NMR, GPC and DSC. It was found that the largest molecular weight ([η]: 0.8745 dL/g) of PGLA5050 was obtained at the irradiation time of 5 min. The color of the copolymers changed from white to light brown, and the yield was higher with the extension of the irradiation time. The molar component ratio of GA in PGLA (FG) was higher than the initial GA feed ratio (nGA) in the raw materials. As the nGA content increased, the glass transition temperature (Tg) of the copolymers decreased and the melting temperature (Tm) of the copolymers increased.

scholarly journals An organocatalytic ring-opening polymerization approach to highly alternating copolymers of lactic acid and glycolic acid

2020 ◽  
Vol 11 (39) ◽  
pp. 6365-6373
Author(s):  
Kaoru Takojima ◽  
Hiroshi Makino ◽  
Tatsuya Saito ◽  
Takuya Yamamoto ◽  
Kenji Tajima ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Glycolic Acid ◽  
Ring Opening Polymerization ◽  
Optically Active ◽  
Alternating Copolymers ◽  
Alternating Copolymer ◽  
Alcohol System

Highly regioselective ring-opening polymerization of optically active methylglycolides was achived using P2-t-Bu/alcohol system to produce alternating copolymer of lactic acid and glycolic acid.

scholarly journals Synthesis and characterization of copoly(L-lactic acid-caprolactone) and its stereo-effect with poly D-lactic acid and biodegradability

2012 ◽  
Vol 47 (2) ◽  
pp. 203-210
Author(s):  
M Amirul Hoque ◽  
A Nakayama ◽  
HP Nur ◽  
SK Raya ◽  
MM Rahman ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Treatment Method ◽  
Ring Opening Polymerization ◽  
Effect Of Temperature ◽  
Feed Ratio ◽  
Synthesis And Characterization ◽  
Enzymatic Method ◽  
Sludge Treatment

Random copolymerizations of L-Lactide with ?-Caprolactone by ring opening polymerization reactions were carried out. A number of copolymers were formed and observed that any composition of copolymer can be formed by changing the feed ratio of the respective monomers. The effect of temperature and time in copolymerization reaction were studied. For their characterization, NMR, IR, DSC and GPC were measured. The stereo-effect of the lactic acid based biodegradable polymers and copolymers for improve thermo-mechanical properties were studied. The obtained copolymers also show stereo-effect like homopolymer. The biodegradability of obtained polymers, copolymers and stereocomplex were studied in three different biodegradation methods; e.g., Enzymatic method, Composting method and Activated Sludge treatment method; and compared to each other. DOI: http://dx.doi.org/10.3329/bjsir.v47i2.11453 Bangladesh J. Sci. Ind. Res. 47(2), 203-210, 2012

Synthesis and synthetic mechanism of Polylactic acid

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xavier Montané ◽  
Josep M. Montornes ◽  
Adrianna Nogalska ◽  
Magdalena Olkiewicz ◽  
Marta Giamberini ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Polylactic Acid ◽  
Ring Opening ◽  
Fossil Fuel ◽  
Raw Materials ◽  
Ring Opening Polymerization ◽  
Bifunctional Catalysts ◽  
Organometallic Catalysts ◽  
Polymer Properties ◽  
Organic Catalyst

AbstractAt present, Polylactic acid (PLA) is one of the most used biodegradable polyesters. The good properties and its biodegradability make that PLA can replace the fossil fuel derived polymers in different applications. PLA can be synthesized by using different methodologies. Among them, the most widely used forms on an industrial scale are the direct polycondensation of Lactic acid and the ring-opening polymerization of cyclic Lactide. The final properties of the obtained PLA are dependent on the used stereoisomers of the raw materials (Lactic acid and/or Lactide) and the conditions employed to polymerize them. Therefore, the comprehension of the synthetic mechanism of PLA is crucial to control the stereoregularity of PLA, which in turn results in an improvement of the polymer properties. So, distinct mechanisms for the synthesis of PLA by ring-opening polymerization using different catalysts systems (organometallic catalysts, cationic catalyst, organic catalyst, bifunctional catalysts) are examined in this review.

scholarly journals Synthesis and Characterization of Polyphosphazenes Modified with Hydroxyethyl Methacrylate and Lactic Acid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Room Temperature ◽  
Block Structure ◽  
Ring Opening Polymerization ◽  
Synthesis And Characterization ◽  
Poly Lactic Acid ◽  
Hydroxyethyl Methacrylate ◽  
H Nmr

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.

scholarly journals Development of Four Unit Processes for Biobased PLA Manufacturing

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chae Hwan Hong ◽  
Si Hwan Kim ◽  
Ji-Yeon Seo ◽  
Do Suck Han
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Lactic Acid Production ◽  
Scale Up ◽  
Catalyst System ◽  
Ring Opening Polymerization ◽  
Acid Fermentation ◽  
Manufacturing Method ◽  
Renewable Biomass ◽  
Microbial Productivity

Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the stereocomplex PLA, we developed the four unit processes, fermentation, separation, lactide conversion, and polymerization. Fermentation of sugars to D-lactic acid is little studied, and its microbial productivity is not well known. Therefore, we investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and we got a maximum lactic acid production 60 g/L. Lactide is prepared by a two-step process: first, the lactic acid is converted into oligo(lactic acid) by a polycondensation reaction; second, the oligo(lactic acid) is thermally depolymerized to form the cyclic lactide via an unzipping mechanism. Through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time 50% the level of the conventional method. Poly(L-lactide) was obtained from the ring-opening polymerization of L-lactide. We investigated various catalysts and polymerization conditions. Finally, we got the best catalyst system and the scale-up technology.

scholarly journals Elucidating a Unified Mechanistic Scheme for the DBU-Catalyzed Ring-Opening Polymerization of Lactide to Poly(lactic acid)

2016 ◽  
Vol 49 (13) ◽  
pp. 4699-4713 ◽  
Author(s):  
Nicholas J. Sherck ◽  
Hyun Chang Kim ◽  
You-Yeon Won
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid

Biodegradable Polymers Derived from Amino Acids for Biological Applications

2010 ◽  
Vol 76 ◽  
pp. 30-35 ◽  
Author(s):  
Naomi Cohen-Arazi ◽  
Ilanit Hagag ◽  
Michal Kolitz ◽  
Abraham J. Domb ◽  
Jeoshua Katzhendler
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Opening Polymerization ◽  
Microwave Assisted Synthesis ◽  
Hydroxy Acids ◽  
Natural Amino Acids ◽  
Direct Condensation ◽  
Positively Charged

Optically active α-hydroxy acids derived from amino acids have been synthesized and polymerized into new biodegradable polyesters. The variety of functional side chains enables the design of positively charged, negatively charged, hydrophobic and hydrophilic chiral building blocks or any combination of these constituents. Hydroxy acids of 15 natural amino acids were prepared with retention of configuration using a straightforward and reliable method of diazotization of α-amino acids. Polyesters were synthesized from these hydroxy acids by a number of methods: direct condensation in bulk, microwave assisted synthesis and ring opening polymerization. The molecular weight of the prepared polymers ranges between 2000 to 5000Da for the direct condensation and the microwave methods, whereas the ring opening polymerization results in high molecular weight polymers (20000 to 30000Da). The polymers were analyzed for their optical activity (Circular Dichroism Spectroscopy), thermal properties (DSC), solubility, molecular weight and polydispersity (GPC), and aqueous degradation. These polymers were tested for their compatibility to neuronal cells growth and differentiation.

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